The research has focused on Kwale County, which has provided a unique setting for understanding the drivers and dynamics of rural water supply sustainability. The region played host to the first large scale deployment of the Afridev handpump, a now ubiquitous technology in many African and Asian countries. The handpump installation programme, which ran for 12 years between 1983 and 1995, has since been held up as a ‘gold standard’ of rural water programming. As a result, a number of relatively rare data sources were available, including a consolidated set of installation records, water committee financial records dating back to the 1980’s, and a glimpse into the divergent operational outcomes over the course of three decades.

Another consequence of the long-running handpump installation programme is that the institutional starting point for operation and maintenance appears to have been relatively consistent. This has allowed for a distillation of how environmental and geographic factors impinge upon operational outcomes. And despite the relatively small area in which more than 500 handpumps in Kwale are situated, our results have consistently showed groundwater characteristics and settlement patterns play an important role in shaping the long term prospects of community water supplies.

Starting with the most recent analysis of handpump lifespans, we found the likelihood of premature failure was higher for water points that supplied water with elevated electrical conductivity (a measure of salinity), pumped water from greater depths, and were underlain by unconsolidated sands. The association with salinity probably reflects a user satisfaction issue – the propensity to pay for ongoing maintenance of a handpump is likely to be diminished when the water tastes salty. This is supported by our earlier findings that palatability was a significant determinant of whether or not a household would pay their monthly fees as well as their decisions about which water source to use. By contrast, the relationships with depth and geology signify differences in the maintenance requirements and the associated financial burden of keeping the handpump in working condition.

Location of the water point also matters. The closer a community was to spare part suppliers, the lower the risk of failure. This could be directly linked to the transaction costs of obtaining spares – or simply be due to other socio-economic confounders. In earlier studies, the proximity of a water point to user households was also found to be a key driver of household contribution rates and water source choices.

These findings show us that there are a variety of environmental and geographic challenges to keeping water supply systems working, and communities are each dealt a different hand. Some factors – such as salinity – may undermine the willingness of users to their sustain system; others – such as groundwater depth or distance to spare parts – may make it more difficult or expensive to do so. It is thus little wonder that rural water supply outcomes are mixed, even if the quality of implementation is high.

How then can service delivery models level the playing field? Clearly, little can be done to change hydrogeological or demographic characteristics. However, their impact could be mitigated. One option is for a centralised approach to maintenance and repairs, whereby a tariff structure allows communities with troublesome hydrogeology to pay the same amount for a maintenance service as those communities enjoying more benign conditions (all else being equal). Such a scheme has been running for more than two decades in Turkana, a region in Northern Kenya that presents extremely challenging conditions for rural water supply operation and maintenance. Other variations on this theme are currently being trialled in Kitui County and in Kwale itself. While we await the results from these initiatives, early evidence suggests they can address the issues relating to more difficult operating conditions, but overcoming inherent differences in willingness to pay is more problematic.

Ultimately, the case of Kwale shows that under favourable conditions, handpump supplies can last more than 25 years. The trick then is how to achieve similar longevity for communities that encounter more troublesome operating environments. Solving this conundrum will be essential if the global target of safe water for all is to be met.